PROJECT SUMMARY The benefits of early spectacle treatment for moderate refractive error in asymptomatic toddlers are not known. AAPOS spectacle prescribing guidelines for children less than 3 years of age are based on consensus and clinical experience because ?there are no scientifically rigorous published data for guidance?. The United States Preventive Services Task Force concluded in 2017 that there is insufficient evidence to assess the balance of benefits of vision screening for children less than 3 years of age because data on the benefits of spectacle correction for refractive error in toddlers are lacking. The SPEC Trial addresses these important gaps in the literature with a focus on assessing the developmental and visual benefits of spectacle treatment for astigmatism in toddlers, and the factors associated with spectacle treatment compliance in this age group. SPEC is a prospective trial to determine if prescribing and providing spectacle correction for astigmatic toddlers (at 12 to < 24 months or 24 to < 36 months of age) meeting current consensus based prescribing guidelines result in better developmental and visual outcome compared to astigmatic children who are prescribed and provided spectacles at age 36 to < 40 months. Developmental outcomes will be measured using the Bayley Scales of Infant and Toddler Development, 3rd Edition. Visual acuity outcome will be measured using the Amblyopia Treatment Study HOTV Protocol. Spectacle treatment compliance will be measured using a wearable sensor attached to the spectacles. The results of the SPEC Trial will have important implications for screening and treatment of young astigmatic children. This study will generate evidence to inform parents, pediatricians, and eye care providers if prescribing spectacles for astigmatic toddlers will have a beneficial effect on their global development, and will allow clinicians to make evidence-based, rather than consensus-based, recommendations regarding treatment of astigmatism in toddlers. The SPEC Trial is also unique in that it includes objective measures of spectacle treatment compliance, and will provide much needed data on factors associated with spectacle treatment compliance in toddlers.